Java spring hibernate jpa中的多对一关系

有人能告诉我如何解决在MySQL数据库上使用hibernate和jpa的SpringMVC应用程序中的以下错误吗

[javax.el.PropertyNotFoundException: Property 'facilities' not found on type   
org.springframework.samples.knowledgemanager.model.ProviderCompany] with root cause
javax.el.PropertyNotFoundException: Property 'facilities' not found on type  
org.springframework.samples.knowledgemanager.model.ProviderCompany

创建基础表的sql是：

CREATE TABLE IF NOT EXISTS providerCompanies(
  id INT(4) UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
  name VARCHAR(80),
  INDEX(name)
);

CREATE TABLE IF NOT EXISTS facilityAddresses(
  id int(11) UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
  company_id int(11) UNSIGNED NOT NULL,
  type_id int(11) UNSIGNED NOT NULL,
  facilityname varchar(50),
  address varchar(200),
  city varchar(200),
  state_id int(11) UNSIGNED NOT NULL,
  zip varchar(50),
  isHQ bool,
  FOREIGN KEY (company_id) REFERENCES providerCompanies(id), 
  FOREIGN KEY (type_id) REFERENCES locationTypes(id),
  FOREIGN KEY (state_id) REFERENCES states(id)

))

ProviderCompany

类别为：

@Entity
@Table(name = "providerCompanies")
public class ProviderCompany extends NamedEntity {
    @ManyToMany(cascade = {CascadeType.ALL})
    @JoinTable(name="companyContactJunction",
            joinColumns={@JoinColumn(name="company_id")},
            inverseJoinColumns={@JoinColumn(name="contact_id")})
    protected Set<OfficeContact> companycontacts = new HashSet<OfficeContact>();

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "company",  fetch=FetchType.EAGER)
    protected Set<FacilityAddress> facilities = new HashSet<FacilityAddress>();

    ////////////OfficeContact methods
    protected void setContactsInternal(Set<OfficeContact> locs) {this.companycontacts = locs;}

    protected Set<OfficeContact> getContactsInternal() {
        if (this.companycontacts == null) {this.companycontacts = new HashSet<OfficeContact>();}
        return this.companycontacts;
    }

    public List<OfficeContact> getContacts() {
        List<OfficeContact> sortedLocs = new ArrayList<OfficeContact>(getContactsInternal());
        PropertyComparator.sort(sortedLocs, new MutableSortDefinition("contact", true, true));
        return Collections.unmodifiableList(sortedLocs);
    }

    public void addContact(OfficeContact oc) {
        getContactsInternal().add(oc);
        oc.addCompany(this);
    }

    public OfficeContact getContact(String fa) {return getContact(fa, false);}

    public OfficeContact getContact(String fa, boolean ignoreNew) {
        fa = fa.toLowerCase();
        for (OfficeContact e : getContactsInternal()) {
            if (!ignoreNew || !e.isNew()) {
                String compName = e.getLastName();
                compName = compName.toLowerCase();
                if (compName.equals(fa)) {return e;}
            }
        }
        return null;
    }
    ////////////Location methods
    protected void setFacilitiesInternal(Set<FacilityAddress> addresses) {this.facilities = addresses;}

    protected Set<FacilityAddress> getFacilitiesInternal() {
        if (this.facilities == null) {this.facilities = new HashSet<FacilityAddress>();}
        return this.facilities;
    }

    public List<FacilityAddress> getFacilities() {
        List<FacilityAddress> sortedLocations = new ArrayList<FacilityAddress>(getFacilitiesInternal());
        PropertyComparator.sort(sortedLocations, new MutableSortDefinition("location", true, true));
        return Collections.unmodifiableList(sortedLocations);
    }

    public void addFacility(FacilityAddress addr) {
        getFacilitiesInternal().add(addr);
        addr.setCompany(this);
    }

    public FacilityAddress getFacility(String address) {return getFacility(address, false);}

    public FacilityAddress getFacility(String addr, boolean ignoreNew) {
        addr = addr.toLowerCase();
        for (FacilityAddress address1 : getFacilitiesInternal()) {
            if (!ignoreNew || !address1.isNew()) {
                String compName = address1.getAddress();
                compName = compName.toLowerCase();
                if (compName.equals(addr)) {return address1;}
            }
        }
        return null;
    }
}

@Entity
@Table(name = "facilityAddresses")
public class FacilityAddress extends BaseEntity{
    @Column(name="address")
    protected String address;

    @Column(name="city")
    protected String city;

    @ManyToOne
    @JoinColumn(name = "state_id")
    protected State state;

    @Column(name="zip")
    protected String zip;

    @ManyToOne
    @JoinColumn(name = "company_id")
    protected ProviderCompany company;

    @ManyToOne
    @JoinColumn(name = "type_id")
    protected LocationType locationType;

    @Column(name = "facilityname")
    protected String facilityname;

    @Column(name = "isHQ")
    protected boolean isHQ;

    @ManyToMany(mappedBy="facilities")
    protected Set<Provider> providers = new HashSet<Provider>();

    public String getAddress(){return address;}
    public void setAddress(String addr){address=addr;}

    public String getCity(){return city;}
    public void setCity(String cty){city=cty;}

    public State getState(){return this.state;}
    public void setState(State st){state=st;}

    public String getZip(){return zip;}
    public void setZip(String zp){zip=zp;}

    protected void setCompany(ProviderCompany pc) {this.company = pc;}
    public ProviderCompany getCompany(){return this.company;}

    public LocationType getLocationType(){return locationType;}
    public void setLocationType(LocationType lt){locationType=lt;}

    public String getFacilityname(){return facilityname;}
    public void setFacilityname(String dir){facilityname=dir;}

    public boolean getIsHQ(){return isHQ;}
    public void setIsHQ(boolean ma){isHQ=ma;}

    public void addProvider(Provider p) {providers.add(p);}
    public Set<Provider> getProviders(){return this.providers;}

    public boolean isNew() {return (this.id == null);}
}

下面是

BaseEntity.java

：

@MappedSuperclass
public class BaseEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    protected Integer id;

    public void setId(Integer id) {this.id = id;}

    public Integer getId() {return id;}

    public boolean isNew() {return (this.id == null);}

}

@MappedSuperclass
public class NamedEntity extends BaseEntity {

    @Column(name = "name")
    private String name;

    public void setName(String name) {this.name = name;}

    public String getName() {return this.name;}

    @Override
    public String toString() {return this.getName();}

}

下面是

NamedEntity.java

：

@MappedSuperclass
public class BaseEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    protected Integer id;

    public void setId(Integer id) {this.id = id;}

    public Integer getId() {return id;}

    public boolean isNew() {return (this.id == null);}

}

@MappedSuperclass
public class NamedEntity extends BaseEntity {

    @Column(name = "name")
    private String name;

    public void setName(String name) {this.name = name;}

    public String getName() {return this.name;}

    @Override
    public String toString() {return this.getName();}

}

JpaProviderCompanyRepository是：

@Repository
public class JpaProviderCompanyRepositoryImpl implements ProviderCompanyRepository {

    @PersistenceContext
    private EntityManager em;

    @SuppressWarnings("unchecked")
    public Collection<ProviderCompany> findByName(String name) {
        System.out.println("---------------------- inside findByName() ");
        Query query = this.em.createQuery("SELECT DISTINCT company FROM ProviderCompany company left join fetch company.facilities WHERE company.name LIKE :name");
        System.out.println("---------------------- just created query. ");
        query.setParameter("name", name + "%");
        System.out.println("---------------------- just set parameter for query. ");
        Collection<ProviderCompany> results = query.getResultList();
        System.out.println("---------------------- just stored query results in collection. ");
        return results;//query.getResultList();
    }

    @Override
    public ProviderCompany findById(int id) {
        // using 'join fetch' because a single query should load both owners and pets
        // using 'left join fetch' because it might happen that an owner does not have pets yet
        System.out.println("<<<<<<<<<<<<<<<<<<<<<<<< inside Jpa Repository findById() >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>");
        Query query = this.em.createQuery("SELECT company FROM ProviderCompany company left join fetch company.facilities WHERE company.id =:id");
        System.out.println("========================= Just set query. ");
        query.setParameter("id", id);
        System.out.println("------------------------- Just added parameter to query. ");
        ProviderCompany pc = (ProviderCompany) query.getSingleResult();
        System.out.println("------------------------- Just created ProviderCompany object from query result. ");
        return pc;
    }

    @Override
    public void save(ProviderCompany company) {
        if (company.getId() == null) {this.em.persist(company);}
        else {this.em.merge(company);}
    }
}

---

这是因为您的

提供商公司

及其超类没有字段

位置

。因此，您不能在查询中使用此不存在的字段

我认为这个错误与JPA无关。从stacktrace判断，这里的问题是Spring MVC无法识别所讨论的属性。为了被SpringMVC识别为属性，变量必须具有javabeans风格的getter和setter。在重新编译代码之后，我发现您缺少的是

facilities

变量的setter，Spring MVC需要它才能为变量赋值

也许可以自定义它，这样您就不必添加您并不真正想要的setter，但我不知道如何添加。关于SpringMVC，我最不喜欢的一件事是它对与其通信的类的要求，这些类通常是域类，您希望保持尽可能干净的类，其中的要求由域逻辑控制，而不是由第三方控制。为每个页面使用单独的命令对象可能会缓解这种情况，但另一方面，它也可能变得混乱

---

一般来说，您的imho中有很多杂乱的内容，比如

@Column

——注释只是将列的名称定义为JPA默认的名称。这些可以删除（以及名称为_id的

@JoinColumn

s，也是默认值）。此外，过度使用特殊字符有点伤我的眼睛：p

我在ProviderCompany中没有看到

设施

属性的任何setter。尝试添加

setFacilities（）

方法。

错误消息很清楚：实体

ProviderCompany

中没有

locations

属性，因此您的JPQL查询是错误的。你期待什么？@DavidLevesque感谢你是第一个看到打字错误的人。我已将

位置

更改为

设施

。我刚刚对上面的代码进行了更改，这揭示了真正的错误。你能帮我解决吗？我已经看了好几天了，还没弄明白。它似乎没有在表

FacilityAddresss

中找到

地址

列。您确定您的数据库模式是最新的，并且连接到了正确的数据库吗？@DavidLevesque再次感谢您提供了非常有见解的答案。我添加了

删除表（如果存在设施地址）到创建数据库并发现新错误的sql，我已经在上面的原始帖子的编辑版本中写到了这个错误。你愿意帮我把这件事做好吗？我试着不在这个问题上发表多个问题，我已经研究这个问题好几天了。就这样做了+我有一个非常类似的问题，只是有一个多对多关系，在这个关系中，我需要一个选择框来填充一个实体的所有可能值的列表，用户从中选择少量值。我试着从这个问题上提出你的建议，但没有用。你能看看我的新问题吗？这里有一个链接：+1，感谢您看到这个问题。同时看到这个问题的其他人也帮助回答了这个线程前面的迭代。